Eggs are a valuable food product known as an important source of nutrients such as proteins, fats, vitamins and minerals. Eggs are also valued as a food for their distinctive flavor, mouthfeel and other organoleptic properties and as such are very desirable for eating by themselves.
The major parts of an egg are the shell composed mostly of calcium carbonate; the white composed mostly of proteins; and the yolk which is mostly a complex mixture of lipids and proteins. Mixtures of egg white and yolk are referred to as whole egg.
Liquid egg products, as the term is used herein, are processed compositions of egg white, yolk of whole egg, optionally including minor amounts of additives such as preservatives, stabilizers, texturizers, or the like. In the United States, egg products are processed to meet Government specifications relating to microbe content, chemical composition, and physical properties. Processing typically involves separating the white and yolks from their shells, pasteurizing and mixing the products thereof with lesser portions of additives. Separation of the shells from the white and yolk usually involves cooling the unbroken eggs to about 10.degree. C., washing, rinsing, santizing, flash candling and thereafter breaking the shells and collecting the yolks and whites separately. Suitable pasteurization techniques are discussed in the Encyclopedia of Chemical Technology, Kirk-Othmer, John Wiley & Sons, Vol. 8, pp. 429-445; the text of which is incorporated herein by reference.
Findings implicating high blood cholesterol levels and high saturated fat intake in humans with the onset and/or severity of cardiovascular disease and public interest in low calorie diets has stimulated the development of modified egg products containing less cholesterol and saturated fat than products made with whole eggs. Whole egg contains about 548 mg cholesterol and 6.7 g of saturated fat per 100 g and all of these constituents are found in the yolk. See: Composition of Foods, Dairy and Egg Products, Raw-Process-Dried, Agriculture Handbook No. 8-1, Agriculture Research Service, U.S.D.A. (1976). Modified liquid egg products having reduced levels of cholesterol and saturated fats may be prepared by removing at least some, and preferably all, of the yolk from the egg white and substituting additives that provide the white with organoleptic properties and coloring similar to whole eggs. The number of calories in such products may be reduced incidentally by the reduction of yolk content.
One example of such a modified egg product is disclosed in U.S. Pat. No. 3,911,144, which is incorporated herein by reference, and which discloses a substantially cholesterol free composition having a high degree of freeze/thaw stability comprising from about 24 to 99.5% wt. egg white and typically from about 0.005 to about 0.3% wt. xantham gum. Such egg products may be refrigerated or frozen and show little or no separation of their components when thawed. The thawed products have a viscosity similar to fresh whole eggs and when cooked, e.g., scrambled, produce a food having organoleptic properties smaller to fresh scrambled whole eggs.
Another example of a low cholesterol/reduced calorie modified egg product that stimulates fresh whole egg in cooked dishes is disclosed in U.S. Pat. No. 4,296,134, which is incorporated herein by reference, which product comprises about 60 to 96 parts by weight liquid egg white; 0 to 18 parts water; 2 to 15 parts of a protein replacement such as nonfat dry milk solids, powdered egg albumin and/or soy protein; and small quantities of stabilizer, flavoring, and coloring. These liquid egg products may be refrigerated or frozen for storage.
Consumer-oriented egg products and modified egg products for preparing popular egg dishes that have the organoleptic properties of fresh whole eggs are highly desirable for their economy, high nutrition, convenience, and appeal as a food. Moreover, egg product dishes which include discrete cheese portions or cheese-flavored particles, i.e. pieces, that are added to eggs before cooking to enhance and modify the natural egg flavors and provide discrete zones of natural or imitation cheese are also very desirable. The cheese solids included in such dishes may be particules of natural and/or synthetic cheese cut to a suitable size for incorporation into egg dishes, such as scrambled eggs, omelets or the like, and large enough to provide discrete regions of the melted cheese solids in the final cooked egg dish.
Egg recipes calling for cheese solids to be added to eggs before cooking are well known in the art, but it has heretofore been practical to add cheese solids to liquid egg products and modified liquid egg products that are to be refrigerated or frozen for substantial periods of time without undesirable softening and disintegration of the cheese particles that cause them to blend with the egg product and lose their structural identity so that they are no longer capable of forming discrete softened or melted cheese solids in cooked egg dishes prepared therefrom. In other words, such egg and cheese products are not storage stable under either refrigerator or freezer temperatures. Thus, the cooked egg dishes prepared from such products after storage have neither the appearance nor organoleptic properties of fresh scrambled eggs, or omelets, with cheese.
The major drawbacks to using many cheese solids in liquid egg products are that they rapidly liquify or melt and agglomerate on standing in the egg products and typically form a gooey mass that adheres to their containers or blends into the egg product. Therefore, when a cooked food such as scrambled eggs is prepared therefrom, the presence of the cheese solid will be unnoticeable in the cooked food, except for whatever it contributes to the overall flavor; or it may form one or a few undersirable large masses of sticky material in the product container or cooked food, e.g. it may lose the texture, consistency and mouthfeel of discrete melted cheese particles in the cooked food. When cheese solids are incorporated into egg products in accordance with the present invention, these drawbacks are avoided.